title: Hemosiderin deposition in the brain as footprint of high-altitude cerebral edema.
abstract: OBJECTIVE
  Based on recent findings of microhemorrhages (MHs) in the corpus callosum (CC) in 3 individuals after nonfatal high-altitude cerebral edema (HACE), we hypothesized that hemosiderin depositions in the brain after high-altitude exposure are specific for HACE and remain detectable over many years.
  
  
  METHODS
  This was a cross-sectional study involving 37 mountaineers in 4 groups: 10 had experienced HACE, 8 high-altitude pulmonary edema, 11 severe acute mountain sickness, and 8 had climbed to altitudes ≥6,962 m without developing any high-altitude illness. HACE was defined as ataxia necessitating assistance with walking and/or decreased consciousness. Within <1 to 38 months after the qualifying incident, MRI of the brain was performed using a 3-tesla scanner and high-resolution susceptibility-weighted magnetic resonance sequences for detection of hemosiderin depositions, which were quantified by a score.
  
  
  RESULTS
  Unequivocal MHs located in the splenium of the CC were found in 8 subjects and questionable MHs were found in 2 subjects 1 to 35 months after HACE. They were located outside the CC in 5 more severe cases. MHs remained unchanged in those reexamined after 12 to 50 months. A few unequivocal MHs in the splenium of the CC were found in one subject after severe acute mountain sickness, while one subject with high-altitude pulmonary edema and 2 of the extreme altitude climbers had questionable lesions. In all other subjects, MHs were unequivocally absent.
  
  
  CONCLUSIONS
  MHs detectable by susceptibility-weighted MRI predominantly in the splenium of the CC are long-lasting footprints of HACE.
authors.affiliation: From the Department of Internal Medicine, Division VII: Sports Medicine (K.S., P.B.), and Department of Neurology, Division of Neuroradiology (K.L.), University Hospital, Heidelberg; and Neuroradiology (K.K., M.K.), University Medicine, Göttingen, Germany.
authors.forename: Kai
authors.initials: K
authors.lastname: Schommer
authors.forename: Kai
authors.initials: K
authors.lastname: Kallenberg
authors.forename: Kira
authors.initials: K
authors.lastname: Lutz
authors.forename: Peter
authors.initials: P
authors.lastname: Bärtsch
authors.forename: Michael
authors.initials: M
authors.lastname: Knauth
mesh_terms: D000532:Altitude Sickness / Q000150:complications* / Q000175:diagnosis / Q000473:pathology; D001921:Brain / Q000378:metabolism*; D001929:Brain Edema / Q000209:etiology* / Q000473:pathology*; D016009:Chi-Square Distribution; D003337:Corpus Callosum / Q000473:pathology; D003430:Cross-Sectional Studies; D005260:Female; D005500:Follow-Up Studies; D006485:Hemosiderin / Q000378:metabolism*; D006801:Humans; D006976:Hypertension, Pulmonary / Q000150:complications*; D008279:Magnetic Resonance Imaging; D008297:Male
chemical_list: D006485:Hemosiderin